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C. L. EIDLITZ.

FUSE PLUG.

APPLICATION FILED APR. 9. ms.

Patented July 15, 1919.

INVE NTOR.

W I TNESS:

ATTORNEY) "18 COLUMBIA muonnAPM cu-. WASHINUIUN. n c.

CHARLES L. EIDLITZ, OF NEW YORK, N. Y.

FUSE-PLUG.

Specification of Letters Patent.

Patented July 15, 1919.

Application filed April 9, 1918. Serial No. 227,422.

To all whom it may concern:

Be it known that 1, CHARLES L. EIDLI'rz, a citizen of the United States,residing at the city of New York, in the borough of Manhattan and Stateof New York, have invented certain new and useful Improvements inFuse-Plugs, of which the following is a full, clear, and exactdescription.

This invention relates to the electrical device known as a fuse plug. Afuse plug ordinarily consists of an insulating body having two externalcontacts and provided with an interior chamber containin a fusibleconductor, the terminals of w ich are in connection with said externalcontacts, the device being adapted to be screwed or otherwise fittedinto a socket containing two con tacts of an electric circuit, which arethereby brought. into connection with the said external contacts of theplug so as to introduce the fusible conductor into the circuit. As theseplugs have been commercially manufactured, the fusible conductor isperma nently secured by solder or some equivalent means to the contactsof the plug and with as great a space as possible between theextremities of the fusible conductor, so that when the fuse is blown itwill be impossible for an arc to form between the contacts of the plug.As thus constructed, it is impractical to replace a destroyed fuse andthe practice has been. therefore, to discard the plug as a whole, andintroduce an entirely new plug whenever a fuse is blown. To avoid thiswaste it is the object of my invention to provide a plug in which thefusible conductor can be readily replaced, and to accomplish this in astructure which will prevent the formation of an are between theterminals when the fuse is blown and which may also be manufactured atlow cost.

My invention consists of a fuse plug comprising an insulating bodyhaving the usual external contacts and provided with a cavity or chamberin which are located two binding posts connected respectively with saidcontacts and which are separated by a barrier or flange so arranged andcombined with a cover for the cavity that it is impossible for an arc toform between the said binding posts. The barrier or flange at the sametime imparts a U-shape to the cavity where in the binding posts occupythe respective legs of the U, and the fusible conductor connected withthe posts extends along the bend of the U, thus affording an elongatedchamber impossible to be traversed by any are between the posts.

The improved fuse plug is illustrated in the accompanying drawing, inwhich Figure 1 is a central section thereof, and

Fig. 2 a plan.

The plug consists essentially of a solid body of insulating material 1,formed at one end to receive externally the usual screw threaded sleeve2 and central button 3 of an Edison base. At the opposite end of thebody 1 is formed a circular cavity 4 concentric with the rear face ofthe body. This cavity is adapted to be closed by a cap 5 having a screwthreaded flange adapted to screw over the outer periphery of the plug,as shown, and provided with a mica disk or window 6, which, when the capis screwed in place, rests snugly against the annular edge of the plugand tightly closes the cavity. 7 is a fin or flange extending from theside wall of the cavity nearly across to the opposite side, but stoppingshort of the same at a point to leave a passage 8 between its extremityand the wall. This fin or flange rises from the bottom of the cavity 4.-and is provided with a straight outer edge, with which the mica disk 6makes contact when the cap is in place to prevent communication betweenthe two parts of the cavity on each side of the flange except around theend thereof, through the passage 8. The cavity is, therefore, by meansof this fin, converted into a U-shaped chamber. In each leg of thisU-shaped chamber is located a binding screw indicated by 9 and 10respectively, the screw 9 being attached to a brass lug 10 leadingthrough the insulating body 1, to the button contact 3 and the screw 10being attached to a lug 12 leading to and connected with the threadedsleeve contact 2. Beneath each screw a pocket is formed in theinsulation to accommodate the end of the screw. 13 is the fusibleconductor, the extremities of which are clamped respectively under theheads of the screws 9 and 10 and the body portion of which leads throughthe passage 8. With this arrangement, it will be seen that the fusibleconductor has considerable length and that when it is destroyed by anexcessive current the fin 7 will act as a barrier to prevent theformation of an are between the two binding posts, communication betweenthe two posts being abmlutely cut oil by the barrier and the mica diskof the cap in all directions except around the end of the barrier, thedistance in this direction being too great to permit of the maintenanceor formation of an are.

It is obvious that upon the destruction of a fuse a new one can readilybe inselted by removing the cap and fastening the ends of the fuse underthe respective screws 9 and 10, thus avoiding the necessity of supplyingan entirely new plug.

I claim:

A f-use plug comprising an insulating body having a cavity in one face,an insulating fin projecting from the bottom of Said cavity andtransversely from one side Wall thereof, a cover for said cavitycomprising a mica disk resting against the outer edge of the fin, twoelectrical terminals located in the cavity on opposite sides of the fin,and a fusible conductor detaehably conneeted with both of said terminalsand leading therefrom around the free end of the fin.

n witness whereof, I subscribe my signatunei CHARLES L. EIDLITZ.

Copies of this patent may be obtained for live cents each, by addressingthe Commissioner of Patents, Wnhlngtou, D. 0."

